Guides for fracture system

ABSTRACT

A prosthetic shoulder implant system includes a prosthetic humeral implant and a version device. The humeral implant includes a catch member aperture and a first locking pin aperture. The version device includes a rotatable member with a body and a flexure member, and a plate with a catch member and a projection contacting the flexure member. A first locking pin extends from the version device and is adapted to mate with the first locking pin aperture. In an unlocked condition of the system, the rotatable member has a first rotated position in which the flexure member is in an uncompressed state and the plate is in a first position, and in a locked condition of the system, the rotatable member has a second rotated position in which the flexure member is in a compressed state and the plate is in a second position proximal of the first position.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation-in-part of U.S. patent applicationSer. No. 14/279,572, filed on May. 16, 2014, the disclosure of which ishereby incorporated by reference herein

FIELD OF THE INVENTION

The present invention relates to guides for determining a desiredposition and orientation of an implant in a fracture setting, and inparticular relates to guides for gauging the height and/or orienting theversion of an implant with respect to at least one bone fragment.

BACKGROUND OF THE INVENTION

A joint replacement procedure is sometimes necessary to repair a jointhaving a diseased or damaged articular surface. Such a procedure mayinvolve removal of the diseased or damaged portions of the joint andreplacing them with a prosthetic implant. This is often a desirableprocedure for ball-and-socket type joints, particularly the shoulder andhip joints. A shoulder joint replacement procedure, for example, ofteninvolves removal of the humeral head and replacement thereof with animplant including a stem and a head. It is important that the implant bepositioned correctly within the joint in order to ensure thatappropriate joint kinematics, including range of motion, are preservedso as to replicate, as closely as possible, those of the original joint.

The structure of prosthetic joint components has been developed to besuited for permanent implantation into the joint and includes featuresthat may promote bony ingrowth, adhesion using cement, press-fit or acombination thereof. Particularly, in the case of implants including astem, such as those used in shoulder arthroplasty, these features aregenerally included on the outside surface of the stem. Such features maynot be well-suited for use during the assessment of joint kinematics.Accordingly, instruments such as trials have been developed to be usedin this part of the procedure. Generally, trials are affixed to the boneduring joint kinematic evaluation and removed therefrom after a properposition for the implant has been determined.

Typically, trials are designed to correspond to an implant in size andshape. In a shoulder arthroplasty procedure, for example, a trial may bedesigned to be temporarily inserted into a prepared medullary canal ofthe humerus in a manner similar to that of an implant. Known trials maytake many forms. For example, an expanding trial stem, such as thatdescribed in U.S. Pat. No. 8,216,320, the entire contents of which arehereby incorporated by reference herein, includes a stem that may beexpanded after insertion into the medullary canal. When using such trialstems, particularly in shoulder replacements, it may be difficult toestablish the proper position and orientation for the implant in thehumerus. It would thus be desirable to have guides that simplify thedetermination of proper positioning of the implant during use of a trialstem.

BRIEF SUMMARY OF THE INVENTION

According to one aspect of the disclosure, a prosthetic shoulder implantsystem includes a prosthetic humeral implant and a version device formeasuring a rotational position of the prosthetic humeral implant. Theprosthetic humeral implant includes a catch member aperture and a firstlocking pin aperture. The version device includes a rotatable member, aplate, and a first locking pin. The rotatable member has a body and aflexure member. The plate has a catch member adapted to mate with thecatch member aperture, and a projection in contact with the flexuremember, the catch member extending from a distal portion of the versiondevice along a first axis. The first locking pin extends from the distalportion of the version device along a second axis non-parallel to thefirst axis and is adapted to mate with the first locking pin aperture.In an unlocked condition of the system, the rotatable member has a firstrotated position in which the flexure member is in an uncompressed stateand the plate is in a first position. In a locked condition of thesystem, the rotatable member has a second rotated position in which theflexure member is in a compressed state and the plate is in a secondposition proximal of the first position.

The prosthetic humeral implant may be a permanent implant stem thatincludes a plurality of indicia for marking the height of the permanentimplant stem. The prosthetic humeral implant may be a trial stem implantthat includes a plurality of indicia for marking the height of the trialstem implant. A biasing member may bias the plate to the first position.The body of the rotatable member may include a first projection incontact with a stopper pin when the rotatable member is in the firstrotated position, the first projection resisting rotation of therotatable member in a first rotational direction. The body of therotatable member may include a second projection in contact with thestopper pin when the rotatable member is in the second rotated position,the second projection resisting rotation of the rotatable member in asecond rotational direction opposite the first rotational direction.

The flexure member may include a first groove, a second groove, and aprojecting portion between the first and second grooves. In the unlockedcondition of the system, the projection of the plate may be positionedwithin the first groove. In the locked condition of the system, theprojection of the plate may be positioned within the second groove. Thesystem may include an intermediate condition in which the rotatablemember is in a third rotated position between the first and secondrotated positions and the projection of the plate contacts theprojecting portion of the flexure member. The flexure member may be at amaximum amount of compression in the intermediate condition of thesystem.

When the catch member is positioned within the catch member aperture,the first locking pin is positioned within the first locking pinaperture, and the system is in the locked condition, a compressive forcemay be maintained between the version device and the prosthetic humeralimplant. The version device may include a plurality of version rodapertures. The version rod apertures may be threaded aperturesconfigured to mate with a version rod. Each of the plurality of versionrod apertures may be angled differently than each other version rodaperture. The plate may include a first slot and the version device mayinclude a first plate pin positioned within the first slot. The firstplate pin may guide movement of the plate between the first position ofthe plate and the second position of the plate. The prosthetic humeralimplant may be a permanent implant stem, and the system may furtherinclude a trial stem including a trial catch member aperture adapted tomate with the catch member, and a trial first locking pin apertureadapted to mate with the first locking pin aperture, the permanentimplant stem including a plurality of height indicia corresponding to aplurality of height indicia of the trial stem.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of an exemplary proximal humerus broken intoa plurality of bone fragments.

FIG. 2 is a cross-sectional view of one embodiment of a trial stem foruse during a shoulder replacement procedure.

FIG. 3A is a perspective view of one embodiment of a height measuringgauge according to aspects of the disclosure.

FIG. 3B is a perspective view of the height measuring gauge of FIG. 3Ashown in partial transparency.

FIG. 3C is an isolated perspective view of a slider member of the heightmeasuring gauge of FIG. 3A.

FIG. 3D is an isolated perspective view of a support member or pointerof the height measuring gauge of FIG. 3A.

FIG. 3E is a cross-sectional view of the pointer taken along line 3E-3Ein FIG. 3D.

FIG. 4A is a perspective view of the trial stem of FIG. 2 attached tothe height measuring gauge of FIG. 3 in a locked configuration with thepointer and slider in a neutral or first position.

FIG. 4B is a perspective view of the trial stem of FIG. 2 attached tothe height measuring gauge of FIG. 3 in a locked configuration with thepointer and slider in an active or second position.

FIG. 4C is a perspective view of the trial stem of FIG. 2 attached tothe height measuring gauge of FIG. 3 in a locked configuration with thepointer in the second position and the slider in the first position.

FIG. 4D is a perspective view of the height measuring gauge of FIG. 3 inan unlocked configuration with the pointer in the second position andthe slider in the first position.

FIG. 5A is a perspective view of one embodiment of a stem implantaccording to aspects of the disclosure.

FIG. 5B is a perspective view of a proximal portion of the stem implantof FIG. 5A.

FIG. 5C is a top view of the stem implant of FIG. 5A.

FIG. 5D is a side view of a proximal portion of the stem implant of FIG.5A.

FIG. 6A is a perspective view of the stem implant of FIG. 5A attached tothe height measuring gauge of FIG. 3 in a locked configuration with thepointer and slider in a second position.

FIG. 6B is a perspective view of the stem implant of FIG. 5A attached tothe height measuring gauge of FIG. 3 in a locked configuration with thepointer and slider in a first position.

FIG. 7A is a perspective view of one embodiment of a version blockaccording to an aspect of the disclosure.

FIG. 7B is a cross-sectional view of the version block of FIG. 7A.

FIG. 7C is an isolated perspective view of a catch member of the versionblock of FIG. 7A.

FIG. 7D is an isolated perspective view of a lever of the version blockof FIG. 7A.

FIG. 7E is a cross-sectional view of the version block of FIG. 7Aattached to the stem implant of FIG. 5A in an unlocked configuration.

FIG. 7F is a cross-sectional view of the version block of FIG. 7Aattached to the stem implant of FIG. 5A in a locked configuration.

FIG. 8A is a side view of a height measurement gauge according toanother aspect of the disclosure.

FIG. 8B is a cross-sectional view of the height measurement gauge ofFIG. 8A.

FIG. 9A is a perspective view of a height measuring gauge according toanother aspect of the disclosure in partial transparency in an unlockedconfiguration.

FIG. 9B is a perspective view of the height measurement gauge of FIG. 9Ain partial transparency in a locked configuration.

FIG. 9C is a side view of a deformable plate and locking statusindicator of the height measurement gauge of FIG. 9A.

FIG. 10A is a perspective vies of a version block according to anotheraspect of the disclosure.

FIG. 10B is a cross-section of the version block of FIG. 10A in a lockedcondition, with a corresponding implant omitted from the view.

FIG. 10C is a cross-section of the version block of FIG. 10A coupled tothe stem implant of FIG. 5A in an unlocked condition.

FIG. 10D is a cross-section of the version block of FIG. 10A coupled tothe stem implant of FIG. 5A in an intermediate condition.

FIG. 10E is a cross section of the version block of FIG. 10A coupled tothe stem implant of FIG. 5A in a locked condition.

FIG. 10F is an enlarged cross section of the version block shown in FIG.10E.

DETAILED DESCRIPTION

In describing preferred embodiments of the disclosure, reference will bemade to the directional nomenclature used in describing the human body.It is noted that this nomenclature is used only for convenience and thatit is not intended to be limiting with respect to the scope of theinvention. When referring to specific directions in relation to adevice, the device is understood to be described only with respect toits orientation and position during an exemplary application to thehuman body. As used herein when referring to bones or other parts of thebody, the term “proximal” means closer to the heart and the term“distal” means more distant from the heart. The term “inferior” meanstoward the feet and the term “superior” means toward the head. The term“anterior” means toward the front part or the face and the term“posterior” means toward the back of the body. The term “medial” meanstoward the midline of the body and the term “lateral” means away fromthe midline of the body. Further, although the devices and methodsdescribed herein are generally described in relation to human shoulderreplacements, it should be understood that the devices and methods arenot intended to be so limited and could be used with other joints, suchas other ball and socket joints, including the hip, for example.

Generally, the replacement of a humeral head with a prosthetic implantduring shoulder arthroplasty involves gaining access to the shoulderjoint through a retracted incision and removing the damaged humeralhead. An exemplary damaged proximal humerus 10 is illustrated in FIG. 1.Although such breaks giving rise to a plurality of bone fragments mayoccur in any number of ways, this particular humerus 10 is broken suchthat a first segment 20, a second segment 30, and a third segment 40including a substantial portion of the humeral head are each detachedfrom the proximal end 12 of the humerus. After removal of the humeralhead 40, the proximal end of the humeral medullary canal may be shapedin order to accept an implant according to known methods. In oneexemplary method, a hand reamer, for example, may be used at a proximalhumeral bearing surface 14 to remove bone material until anappropriately-shaped opening is formed in the proximal end 12 of humerus10 for receiving an implant. Typically, successive reamers of increasingsize are used in order to form an opening of the desired size. In manycases, bearing surface 14 may not be as flat as shown. Most surfaces ata fracture site are irregularly shaped unless there is a clean breakbetween adjacent fragments. Such a surface may be resected into agenerally flat shape to receive a corresponding bearing surface of atrial and/or implant stem as shown in FIG. 1.

Once an appropriate bearing surface 14 and opening is formed forreceiving an implant, trialing is conducted to determine the proper sizeand location for the implant prior to implantation thereof. According toone example of the present disclosure, trialing includes inserting atrial stem 100, as illustrated in FIG. 2, into the opening in theproximal end 12 of humerus 10. Trial stem 100 may include a proximalportion 110 connected to a distal portion 120, for example by welding,with an expansion bolt 130 positioned within the trial stem. Generally,proximal portion 110 is adapted for insertion into the proximal end 12of a prepared humerus 10. Proximal portion 110 may include a catchaperture 112, a trial recess 114, two locking pin apertures (not visiblein FIG. 2), and a driver recess 118. Catch aperture 112 and the lockingpin apertures may be configured to mate with corresponding features on aheight measuring gauge 200, for example, as described in greater detailbelow with respect to FIG. 3A. Trial recess 114 may be shaped to receivea corresponding portion of a trial humeral head (not shown) or a reversecup humeral trial, such as that described in U.S. Pat. No. 8,545,511,the entire contents of which are hereby incorporated by referenceherein. Trial recess 114 may have a longitudinal axis that is angledwith respect to a longitudinal axis of distal portion 120 so as tosubstantially replicate the typical geometry of a shaft and neck of thenative bone prior to a fracture situation as shown in FIG. 1.

The distal portion 120 of trial stem 100 may be structured to fit withina prepared bone canal, preferably the medullary canal of the humerus 10.Distal portion 120 projects along a longitudinal axis thereof fromproximal portion 110 generally in the proximal-to-distal direction.Distal portion 120 may include a first arm 122 and a second arm 124configured to move away from each other in cooperation with expansionbolt 130, such as that described in U.S. Pat. No. 8,216,320, the entirecontents of which are hereby incorporated by reference herein. Distalportion 120, or a portion thereof, may define a cavity or be configuredto accept expansion bolt 130, the cavity including a mating surface suchas threads.

Expansion bolt 130 may generally include a shaft 132 with a pointeddistal tip 134. A proximal end of expansion bolt 130 may include a head136, which may include a recess, such as a hex recess, to cooperate witha correspondingly shaped driving tool (not shown). A proximal end ofshaft 132 may include a mating surface, such as threads 138, configuredto mate with a corresponding surface in the cavity of distal portion120. Although proximal portion 110, distal portion 120, and expansionbolt 130 may each be separate pieces prior to assembly, trial stem 100is preferably provided to the end user as a single piece with theproximal and distal portions permanently connected, for example bywelding, with the expansion bolt contained therein.

After trial stem 100, which may be one chosen from a set of differentlysized trial stems, is inserted into the opening in the proximal end 12of humerus 10, the trial stem may be temporarily secured into place byexpanding the distal portion 120. To expand the distal portion 120, auser may insert a driving tool (not shown) through driver recess 118 inthe proximal portion 110 of the trial stem until the driving tool mateswith the corresponding surface of the head 136 of expansion bolt 130.Rotating the driving tool may engage the threads 138 of expansion bolt130 with corresponding threading in distal portion 120, driving theexpansion bolt distally and causing first arm 122 to be separated fromsecond arm 124, thus causing expansion of the distal end of distalportion 120. This expansion may result in a tighter fit of trial stem100 in humerus 10. Geometrical stops may be included in one or both ofexpansion bolt 130 and distal portion 120 to limit the distance whichthe expansion bolt my travel in the proximal-to-distal direction. Forexample, the size of head 136 or a portion of the proximal shaft ofexpansion bolt 130 may be larger than certain portions of the cavity inthe distal portion 120 of trial stem 100, such that advancement of theexpansion bolt is limited to a particular range of movement.

According to known methods, a height of trial stem 100 with respect tothe medullary canal of the humerus 10 in which the trial stem ispositioned may be noted by a user by, for example, observing indiciaprinted or otherwise marked on the trial stem with respect to bearingsurface 14, for example. This height would be noted to ensure properplacement of a corresponding humeral stem implant. However, in anotherembodiment according to the present disclosure, a height measuring gauge200, as illustrated in FIGS. 3A-B, may be connected to trial stem 100prior to insertion into the medullary canal, and then used to inserttrial stem into the medullary canal and to objectively mark the heightof the trial stem with respect to a location or surface of the intacthumerus, such as bearing surface 14, for example. Height measuring gauge200 may include a handle portion 210 which may have a flexure springassembly similar to the broach handle described in U.S. Pat. No.8,449,548 (“the '548 Patent”), the entire contents of which are herebyincorporated by reference. Handle portion 210 may generally include ahandle body 212, a deformable plate 214 positioned at least partiallywithin handle body 212, and a loading member 216 configured to interactwith the deformable plate. A distal end of deformable plate 214 mayinclude a catch element 218 extending therefrom, and a distal end ofhandle body 212 may include a pair of locking pins 220 extendingtherefrom. Briefly, as a user actuates loading member 216 by rotatingthe loading member clockwise (transition illustrated from FIG. 3A toFIG. 3B), a cam on the loading member interacts with deformable plate214, generally pushing the plate proximally. If handle portion 210 isnot attached to any device, such actuation will not deform deformableplate 214. However, when catch element 218 is positioned inside catchaperture 112 of trial stem 100 and locking pins 220 are positionedinside the locking pin apertures of the trial stem, actuating loadingmember 216 causes the deformable plate 214 to deform, locking the trialstem to the handle portion 210 of height measuring gauge 200. Thismechanism is described in greater detail in the '548 Patent.

It should be noted that a stabilizing mechanism, such as a pin 222extending from a proximal portion of deformable plate 214 and fixedwithin a corresponding cavity defined by handle body 212, for example bywelding, may be provided to apply a downward force on deformable plate214. Pin 222 may be fixed to body 212 while deformable plate 214 isunder some amount of compression. This configuration of pin 222 anddeformable plate 214 may, for example, stabilize deformable plate 214 sothat it does not move or “rattle” around within body 212 when loadingmember 216 is placing little or no force on deformable plate 214. Itshould further be noted that handle body 212 may include a driveraperture 224 extending the length of the body and configured to alignwith driver recess 118 of trial stem 100, such that when handle portion210 is attached to the trial stem, a driving tool may be passed throughthe handle body, through the proximal portion 110 of the trial stem, andinto the head 136 of expansion bolt 130 to allow driving of theexpansion bolt.

Height measuring gauge 200 may also include a height measurement system230. Height measurement system 230 may generally include a slider 240and a height reference member in the form of pointer 250. Slider 240,illustrated alone in FIG. 3C, may generally include a main body 242,flanges 244, one or more ball plungers 246, and a bone positionindicator 248 extending distally from the main body. The bone positionindicator 248 may take the general form of an elongated slendercylindrical rod and may be integral or monolithic with slider 240. Mainbody 242 may include a relatively large portion configured to fit withina track defined by handle body 212, and a relatively small portionconfigured to extend through the track to the outside of the handlebody. This configuration is illustrated as generally rectangular membersfitting within rectangular grooves, but may take other forms, such as adovetail configuration. This configuration provides main body 242 theability to slide proximally or distally down the track in handle body212 while being securely maintained therein. At least one flange 244,and preferably two, may extend from main body 242 and be configured towrap around an outer portion of handle body 212. Flanges 244 may includetexturing, such as ridges, to provide a gripping surface for a user. Oneor more ball plungers 246 may be imbedded in main body 242. In theillustrated configuration, a first pair of ball plungers 246 ispositioned on a proximal end of main body 242 (only one visible in FIG.3C) and another pair of ball plungers 246 is positioned on a distal endof the main body (only one visible in FIG. 3C). Generally, each ballplunger 246 may be spherical and biased away from main body 242 by aspring or spring-like member, although such biasing is not required. Theball plungers 246 may contact a wall of the track in handle body 242,providing frictional engagement therewith. A user may grip one or moreflanges 244 to slide the slider 240 proximally or distally along thetrack, with ball plungers 246 facilitating such sliding motion whilealso providing friction to keep main body 242 generally in place when asliding force is not being provided by a user. In other words, ballplungers 246 help prevent free sliding of slider 240 when no force isbeing applied to the slider. As will be explained in greater detailbelow, sliding main body 242 also slides bone position indicator 248,which may be used to determine a position of the humerus 10, and inparticular the bearing surface 14 of the proximal portion 12 of thehumerus.

The pointer 250 of height measurement system 230, illustrated alone inFIG. 3D, may generally include a main body 252, flanges 254, and one ormore knobs 256. Main body 252 may be of a similar shape to the main body242 of slider 240, with a relatively large portion configured to fitwithin a track defined by handle body 212, and a relatively smallportion configured to extend through the track to the outside of thehandle body. Main body 252 may also include an aperture 253 extendingthe length of the main body in a proximal-to-distal direction, theaperture being sized and configured to accept the bone positionindicator 248 of slider 240 therethrough. At least one flange 254, andpreferably two, may extend from main body 252 and be configured to wraparound an outer portion of handle body 212. Each flange 254 may includea knob 256. Knobs 256 may include threaded screws such that rotating theknobs in one direction drives the screws toward the center of pointer250. When pointer 250 is connected to handle portion 210 such that mainbody 252 is positioned inside the track defined by handle body 212 andflanges 254 are on the outside of the handle portion, rotating the knobs256 may cause the threaded screws to drive into frictional engagementwith the handle body, causing the pointer to lock in its currentposition.

FIG. 3E illustrates a cross sectional view of pointer 250 taken alongthe line 3E-3E of FIG. 3D. A portion of main body 252 adjacent aperture253 may define a cavity 257. Cavity 257 may include a magnet 258 and acap 259, the cap acting to keep the magnet within the cavity. Magnet 258is configured to cause engagement between a distal facing surface of themain body 242 of slider 240 and a proximal facing surface of pointer250, such that during sliding motion of the slider, the pointer willslide along with the slider as long as the pointer is in an unlockedconfiguration. The coupled movement of the slider 240 with respect tothe pointer 250 may be referred to as a first mode of operation. Whenslider 240 is at a desired location, as will be explained in greaterdetail below, pointer 250 will be at a corresponding desired location.At this point, the one or more knobs 256 may be rotated or tightened tokeep pointer 250 in the desired location, with slider 240 removed. Thefrictional force of knobs 256 with handle body 212 is preferably greaterthan the attractive force between magnet 258 and the distal portion ofthe main body 242 of slider 240, such that removing the slider 242 doesnot cause pointer 250 to change positions once the pointer is in thelocked configuration. The decoupled movement of the slider 240 withrespect to the pointer 250 may be referred to as a second mode ofoperation.

As noted above, in an embodiment according to the present disclosure,height measurement gauge 200 may be connected to trial stem 100 prior toinsertion into the medullary canal, and then used to insert the trialstem into the medullary canal and to objectively mark the height of thetrial stem. Once height measuring gauge 200 is locked onto trial stem100, as described above and illustrated in FIG. 4A, the trial stem isinserted into the previously formed opening to the medullary canal inthe proximal portion 12 of humerus 10. If the user determines that adifferent sized trial stem 100 is desirable at this point, the user mayremove the height measuring gauge 200 and trial stem 100, disconnect theoriginal trial stem, and attach a differently sized trial stem to theheight measuring gauge. If the trial stem 100 is an appropriate size,the user may continue. At this point, slider 240 and pointer 250 are ina first or initial proximal position, with the pointer attached to theslider via magnet 258 as described above. Pointer 250 is also in anunlocked configuration. To facilitate the initial choice of anappropriately sized trial stem 100, handle 210 may include a pluralityof indicia, such as gradations 211 (only illustrated in FIG. 4A) thatmay referenced in concert with a contralateral X-ray template of thehealthy bone. The contralateral X-ray template may include correspondingmarkings as handle 210 to facilitate the choice of an appropriatelysized stem 100.

Once trial stem 100 is inserted into humerus 10 to a desirable depth asdetermined by the user, a driving tool may be inserted through thedriver aperture 224 in handle portion 210, through driver recess 118 ofthe proximal portion 110 of trial stem 100, and finally mate the drivingtool with the head 136 of expansion bolt 130. The driving tool may berotated, torqued, or otherwise used to drive expansion bolt 130, causingexpansion of the first and second arms 122, 124 of the distal portion120 of trial stem 100, causing the trial stem to have a snug fit withinthe proximal portion 12 of humerus 10.

Before or after causing such expansion, the user may grip slider 240 andslide it distally until a distal end surface 249 of bone positionindicator 248 makes contact with a bearing surface 14 of the humerus,the position of slider 240 and pointer 250 being shown in FIG. 4B. Atthis stage, knobs 256 may be tightened to frictionally engage handlebody 212. Pointer 250 may now serve as an objective reference to aheight of trial stem 100 with respect to humerus 10 for later reference.Because pointer 250 is frictionally locked, slider 240 may be slidproximally while the pointer remains in place, the magnetic interactionbetween magnet 258 and the main body 242 of the slider not affecting theposition of the pointer, as illustrated in FIG. 4C. Once pointer 250 islocked into the desired position and slider 240 is back at an originalproximal position, handle portion 210 may be shifted to the unlockedconfiguration by actuating loading member 216 as described above. Thisallows a user to remove height measuring gauge 200, as shown in FIG. 4D,while leaving trial stem 100 expanded in place.

With trial stem 100 secure in place, any one of a number of additionaltrial components may be attached to trial stem 100 via trial recess 114,such as a trial humeral head or a reverse cup humeral trial (not shown).One benefit of the trial stem 100 illustrated herein is that the trialrecess 114 may provide compatibility with a greater number of othertrial components compared to known expandable trial stems that have aprotruding peg or similar protruding structure onto which other trialcomponents fit. The position of trial recess 114 is possible at leastpartly due to the location of expandable bolt 130. In certain knownexpandable trial stems, an expansion bolt extended close to the proximalend of the known trial stem, making such a trial recess incompatible asany component inserted into a recess made in the known trial would makecontact with a proximal end of the expansion bolt. However, therelatively distal position of expansion bolt 130 and its totalencapsulation within trial stem 100, as disclosed herein, facilitatesthe ability of using trial recess 114 which, as noted above, may accepta number of different types of trial components. Once the desired trialcomponent is connected to trial stem 100, the user may conduct trialingto confirm the size and placement of trial stem 100 as well as any othertrial components being used.

After the user is satisfied with the results of trialing, any trialcomponents still connected to trial stem 100 may be removed. Trial stem100 may then be removed, with or without the use of height measuringgauge 200. Based on the results of trialing, a particular sized stemimplant 300 is chosen. An exemplary embodiment of stem implant 300 isillustrated in FIG. 5A and may be structurally similar to trial stem 100in certain respects. Stem implant 300 may be monolithic with a proximalportion 310 and a distal portion 320. Proximal portion 310 of stemimplant 300, shown in greater detail in FIGS. 5B-D, may include a catchaperture 312, an implant recess 314, and two locking pin apertures 316.The apertures 312, 316, similar to corresponding features on trial stem100, facilitate the connection between handle portion 210 of heightmeasuring gauge 200 with stem implant 300. Implant recess 314 may beconfigured to accept a humeral head implant, reverse cup humeralimplant, or other compatible implant. Proximal portion 310 may alsoinclude a number of features to facilitate securing portions of humerus10, such as first segment 20 and second segment 30, to stem implant 300.For example, a first pair of suture holes 317 a may be formed on alateral-anterior side of proximal portion 310 and a second pair ofsuture holes 317 b may be formed on a lateral-posterior side of theproximal portion. A third pair of suture holes 317 c may be formed on amedial side of proximal portion 310. The suture holes 317 a-c mayfacilitate securing one or more bone fragments to stem implant 300 viasutures (not illustrated). One suture pocket 319 a may be formed on thelateral-anterior side of proximal portion 310, and may be connected tosuture holes 317 a. Another suture pocket (not visible in FIGS. 5A-D)may be formed on the lateral-posterior side of proximal portion 310, andmay be connected to suture holes 317 b. The suture pockets may, forexample, facilitate the insertion of a suture needle.

After the desired stem implant 300 is chosen, the user may connect thestem implant to height measuring gauge 200 and lock the stem implantusing loading member 216, as described above. Once locked into place, auser may insert stem implant 300 into the prepared hole in humerus 10using height measuring gauge 200. At this stage, pointer 250 is stilllocked into the position determined during insertion of trial stem 100,described above in relation to FIGS. 4A-C. The user may slide slider 240distally until it contacts pointer 250, as illustrated in FIG. 6A. Theuser may confirm that the distal end of bone position indicator 248 isin contact with bearing surface 14 of the proximal portion 12 of humerus10. This confirms that the height of stem implant 300 with respect tohumerus 10 corresponds to the desired height determined using trial stem100, reducing or eliminating the requirement for the user tosubjectively assess the respective heights.

The user may assess and confirm a correct rotational position of stemimplant 300 at this point using one or more of threaded apertures 260,270, and 280, as shown in FIG. 4B. Each threaded aperture 260, 270, and280 is a threaded aperture at varying angles. For example, one of thethreaded apertures may be angled at approximately 20 degrees, anothermay be angled at approximately 30 degrees, and the third may be angledat approximately 40 degrees. A version rod taking the form of a straightrod with a threaded end may be threaded into any one of the threadedapertures 260, 270, or 280. The version rod may be used to provide aline of reference for comparison, for example, with the position of theforearm relative to the shoulder. When the version rod aligns with thedesired anatomical landmark(s), the angle will be known or estimatedbased on which threaded aperture 260, 270, or 280 the version rodextends from. More or fewer than three threaded apertures may beprovided, and the particular angles are not limited to 20, 30, and 40degrees. Further, threaded apertures may be provided on one or bothsides of handle 210. This procedure is essentially the same whethermeasurements are being taken in relation to trial stem 100 or stemimplant 300.

Once version has been confirmed, the user may then unscrew the knobs 256of pointer 250, causing the pointer to transition into an unlockedconfiguration. Then, slider 240 may be slid proximally, causing pointer250 to slide proximally due to the magnetic connection between thepointer and slider, as illustrated in FIG. 6B. Finally, the user mayrotate loading member 246 to unlock handle portion 210 of heightmeasuring gauge 200 from stem implant 300. At this point, the user mayattach a humeral head or other implant component to stem implant 300,and complete the particular implant procedure desired.

As noted above, during the procedure, it may be desirable to assess andconfirm a correct rotational position of trial stem 100 and/or stemimplant 300. One method of assessing and/or confirming version wasdescribed above in relation to threaded apertures 260, 270, and 280 ofhandle 210. A version block 400, as illustrated in FIG. 7A, may be usedin conjunction with a version rod (not illustrated) to determine therotational position of stem implant 300 or trial stem 100 if a user doesnot wish to use threaded apertures 260, 270, and 280 of handle 210.Generally, version block 400 is a monolithic structure with a number ofcomponents that facilitate locking of the version block to stem implant300. In particular, version block 400 may include a pair of locking pins420 configured to mate with locking pin apertures 316 of stem implant300. Version block 400 may also include a catch member 418 configured tomate with catch aperture 312 of stem implant 300. As illustrated in FIG.7B, version block 400 may also include a driver recess 419 configured toallow passage of a driving tool through the version block and into trialstem 100 when the version block is attached to the trial stem.

Still referring to FIG. 7B, the locking mechanism of version block maygenerally include catch member 418, spring cap 450, spring 460, lever470, and actuator 480. Catch member 418, which is also illustrated inFIG. 7C, may be a generally cylindrical member with a flange thatcooperates with spring 460, the spring contacting the flange of thecatch member on a first end and spring cap 450 on a second end oppositethe first end. This configuration provides for a force that biases catchmember 418 beyond a distal end of version block 400. A distal end of theflange of catch member 418 may be configured to contact a proximal faceof lever 470, with a cylindrical portion of the catch member extendingthrough a slot 472 in the lever. Lever 470, which is also illustrated inFIG. 7D, is configured to pivot about pin 490, the pin connecting thelever to version block 400 through a pin aperture 474 in the lever. Theflange of catch member 418 does not fit through slot 472 in lever 470,so the biasing force provided by spring 460 on the catch member istransmitted to the lever, causing the lever to be biased in acounterclockwise direction in the view of FIG. 7B. One end of lever 470is configured to contact a distal end of actuator 480. Actuator 480 maygenerally comprise a cylindrical pin with an enlarged head 482 and aslot 484. Actuator 480 is connected to version block 400 by another pin490 extending through slot 484 of the actuator. Actuator 480 may slideinto or out of version block 400, the sliding motion being limited byenlarged head 482 and the cooperation of pin 490 with slot 484. Asshould be understood from the description of the components above,actuator 480 is biased in a proximal direction resulting from thetransmission of force from spring 460 to catch member 418 to lever 470and finally to the actuator. Thus, a user may press distally on theenlarged head 482 of actuator 480 to cause catch member 418 to retractwithin the body of version block 400. Similarly, a user may stop theapplication of force on the enlarged head 482 of actuator 480 to causethe spring 460 to push catch member 418 partially out of version block400.

To lock version block 400 to stem implant 300, a user depresses actuator480 to retract catch member 418 inside the version block. Locking pins420 are inserted into corresponding locking pin apertures 316 of stemimplant 300, as illustrated in FIG. 7E. The user then aligns catchmember 418 with catch aperture 312 and releases actuator 480, causingthe bias force provided by spring 460 to push the catch member distallyout of version block 400 and into corresponding catch aperture 312 ofstem implant 300, as illustrated in FIG. 7F. Once in the lockedconfiguration, a version rod (not illustrated) may be inserted into anyone of a number of version rod apertures 495 in version block 400, asillustrated in FIG. 7A. The version rod may be generally “L” shaped orstraight, as noted above, with one end of the rod extending to provide aline of reference for comparison, for example, with the position of theforearm relative to the shoulder. As noted above, version block 400 maybe used with trial stem 100 or stem implant 300 to assess the rotationalposition of the trial stem or stem implant in relation to the anatomyduring trialing or assessment of implant position. Because version rodsare generally known in the art, they are not described in greater detailherein.

An alternate embodiment of height measurement gauge 200′ is illustratedin FIGS. 8A-8B. Height measurement gauge 200′ is similar to heightmeasurement gauge 200 in nearly all respects, with the exception of thefollowing. The height measurement system only includes a sliding member240′, without a pointer as provided with height measurement gauge 200.Sliding member 240′ may include a marking, such as an arrow or a notch,to reference corresponding indicia 211′ on the handle body 210′ ofheight measurement gauge 200′. During insertion of trial stem 100,slider 240′ is slid distally until a distal end surface 249′ of boneposition indicator 248′ makes contact with a bearing surface 14 of thehumerus, much in the same way as described in connection with heightmeasurement gauge 200. In this embodiment, the user may take note of theposition of the arrow or other indicator on sliding member 240′ withrespect to indicia 211′ on the body of handle 210′. This provides anobjective indication of the position of bone position indicator 248′when trial stem 100 is properly inserted into the bone. When insertingstem implant 300 using height measurement gauge 200′, sliding member240′ may be positioned so that the arrow or other indicator aligns withthe corresponding indicia 211′ as determined while using trial stem 100.In addition, sliding member 240′ may include teeth, screws, or othermembers to lock the sliding member 240′ in a particular position withrespect to the body of handle 210′. For example, a structure similar toknobs 256 of pointer 250 may be used with sliding member 240′ to achievesuch locking.

Another embodiment of height measuring gauge 200″ is illustrated inFIGS. 9A-B. Height measuring gauge 200″ is nearly identical to heightmeasuring gauge 200, with the exception that height measuring gauge 200″includes a locking status indicator mechanism, for example lockingstatus pin 290″. Pin 290″ extends from a proximal portion of deformableplate 214″ and is positioned within a corresponding cavity defined byhandle body 212″. Pin 290″ may be welded or otherwise fixed todeformable plate 214″ but free to slide within the corresponding cavitydefined by handle body 212″. Pin 290″ may help indicate to the userwhether loading member 216″ is in a locked or unlocked configuration.For example, when in an unlocked configuration, as shown in FIG. 9B, pin290″ may be generally flush with a proximal end of handle body 212″.After a transition to a locked configuration, as shown in FIG. 9B, pin290″ may be pushed proximally so as to extend beyond the proximal end ofhandle body 212″, providing a user with a visual indication that loadingmember 216″ is in a locked configuration. The length and position of pin290″ may be altered to vary the exact position of the pin that indicatesthe locked or unlocked configuration. Deformable plate 214″ and pin 290″are illustrated without handle body 212″ in FIG. 9C.

FIG. 10A is a perspective view of a version block 500 that combinesaspects of the various handles and version blocks described above.Version block 500 may be a monolithic structure with a number ofcomponents that facilitate locking of the version block to trial stem100 and/or stem implant 300. In particular, version block 500 mayinclude a pair of locking pins 520 (only one visible in FIGS. 10A)configured to mate with the locking pin apertures of trial stem 100 andlocking pin apertures 316 of stem implant 300. Version block 500 mayalso include a catch member 518 configured to mate with catch aperture112 of trial stem 100 and catch aperture 312 of stem implant 300. Thecatch member 518 and locking pins 520 may extend from the distal end ofthe version block 500 at non-parallel angles. Version block 500 mayinclude a driver recess 519 configured to allow passage of a drivingtool through the version block and into trial stem 100 when the versionblock is attached to the trial stem.

FIG. 10B illustrates a cross-section of version block 500. The lockingmechanism of version block 500 may generally include a loading member516, which may be a rotatable handle, and a plate 514 which includescatch member 518. Catch member 518 may be a generally cylindrical membercoupled to a distal end of plate 514. An actuator 580 may include adistal tip that may fit within a recess in the proximal end of plate514. Actuator 580 may be a pin and include a proximal cap that is fixedwith respect to the housing of version block 500, with a spring 582positioned around actuator 580, with a proximal end of the springabutting the proximal cap of the actuator. A distal end of spring 582may abut a proximal end of plate 514. Plate 514 may include one or morevertical slots that engage with pins 590, so that the plate is able tomove vertically with the slots sliding over the pins. With thisconfiguration, spring 582 biases plate 514 to a distal position relativeto the version block 500 in the absence of applied forces. This positionmay be referred to as an unlocked condition and is shown in FIG. 10C.Plate 514 may include a hooked projection 517 that interacts withloading member 516 to assist in transitioning the version block from anunlocked condition, shown in FIG. 10C, through an intermediate conditionshown in FIG. 10D, to a locked condition, shown in FIGS. 10E-F, asdescribed in greater detail below.

Referring to FIG. 10C, while version block 500 is in the unlockedcondition, catch member 518 may be inserted into the catch memberaperture 312 of the stem implant 300 (or the corresponding catch memberof the trial stem 100) and locking pins 520 may be inserted into thelocking pin apertures 316 of the stem implant (or the correspondinglocking pin apertures of the trial stem). Loading member 516 includes abody 570 with an aperture that a pin 590 may pass through so that theloading member is rotatable about the pin. Body 570 may include a pairof projections 571 that are positioned on either side of a stopper pin592, which may be similar or identical in structure to the other pins590. The projections 571 may limit the range which the loading member516 may rotate, with the projections contacting the stopper pin 592 atthe maximum ranges of rotation in either direction. Loading member 516may also include a flexure member 572 that has a first end coupled toloading member 516 and a second free end 573. Flexure member 572 may begenerally “U”-shaped so that the flexure member extends in a firstdirection from its connection point to loading member 516, and thenturns back so that the second free end 573 is substantially parallel tothe first end of the flexure member. With this configuration, the secondfree end 573 may move toward (or away from) the first end of flexuremember 572 as compressive force is applied to (or released from) thesecond free end 573.

The second end 573 of flexure member 572 may include a projection 574,with grooves 575, 576 on either side of the projection. In the unlockedcondition of version block 500, shown in FIG. 10C, the projection 517 ofplate 514 may rest within groove 575. One of the projections 571 of body570 of loading member 516 may help ensure that the flexure member 572cannot be rotated so that the projection 517 loses contact with theflexure member. With the catch member 518 within the catch aperture 312of implant stem 300 (or otherwise within the corresponding catchaperture of the trial stem 100), the user may begin to rotate loadingmember 516 clockwise in the view of FIG. 10C. As the loading member 516is rotated clockwise about pin 590, the projection 517 of plate 514begins to ride up the second end 573 of flexure member 572 towardprojection 574, as shown in FIG. 10D. In the intermediate condition ofversion block 500, shown in FIG. 10D, the flexure member 572 begins tocompress as the second end 573 of the flexure member moves toward thefirst end. As the projection 517 rides up the flexure member 572 towardprojection 574, plate 514 is pulled proximally causing spring 582 tocompress. The user may continue to rotate loading member 516 untilprojection 517 passes over projection 574 and comes to rest in groove576 and the version block 500 is in the locked condition shown in FIG.10E. Once the projection 517 passes over projection 574, the flexuremember 572 springs back to relieve some of the compressive forcespreviously applied on the flexure member. In the locked condition, thecatch member 518 is pulled proximally in catch aperture 312 of stemimplant 300 (or the corresponding catch aperture in trial stem 100).Similar to the other embodiments described herein, the force applied tocatch member 518 combined with the positioning of locking pins 520within corresponding locking pin apertures 316 of stem implant 300 orcorresponding locking pin apertures of trial stem 100, results in theversion block 500 being locked to the stem implant or trial stem. Oncethe version block 500 is in the locked condition of FIGS. 10E-F, theuser may release the loading member 516. The projection 574 of flexuremember 572 maintains the projection 517 of plate 514 in groove 576 inthe absence of applied force. Further, the flexure member 572, in thelocked condition of the version block 500, applies an upward force onplate 514 so that version block 500 maintains a compressive force on thestem implant 300 or trial stem 100. The second projection 571 of themain body 570 may interact with stopper pin 592 to limit furtherrotation of the loading member 516 in the clockwise direction.

When version block 500 is in the locked condition, the trial stem 100may be inserted into the proximal humerus 12 and then expanded bypassing a driver tool through the driver recess 519 and expanding thetrial as described in connection with other embodiments above. Theheight of the trial stem 100 may be determined, for example by usingindicia or other markings on the trial stem that correspond to heightindicia or markings on stem implant 300. Version may be confirmed byusing a version rod with one or more version rod apertures 595, insubstantially the same manner as described in connection to versionblock 400. If the trialing is successful, the user may de-expand thetrial stem 100 and remove trial stem 100 from the humerus 12 by pullingthe version block 500 proximally The version block 500 may betransitioned to the unlocked condition and decoupled from the trial stem100. While in the unlocked condition, version block 500 coupled to stemimplant 300, and transitioned back to the locked condition. The stemimplant 300 may then be inserted into the proximal humerus 12 until theheight markings or indicia on the stem implant are at the heightpreviously recorded from the trial stem 100. Version may again beconfirmed using a version rod (not shown) with version rod apertures595, in substantially the same manner as described in connection withother embodiments above. If the implant position is satisfactory, theuser may transition the version block 500 to the unlocked condition andremove the version block from the stem implant 300, leaving the stemimplant in place. Additional components, such as a prosthetic humeralhead, may be coupled to the stem implant 300 and the procedurecompleted.

Although the invention herein has been described with reference toparticular embodiments, it is to be understood that these embodimentsare merely illustrative of the principles and applications of thepresent invention. It is therefore to be understood that numerousmodifications may be made to the illustrative embodiments and that otherarrangements may be devised without departing from the spirit and scopeof the present invention as defined by the appended claims.

1. A prosthetic shoulder implant system comprising: a prosthetic humeralimplant including a catch member aperture and a first locking pinaperture; and a version device for measuring a rotational position ofthe prosthetic humeral implant including: a rotatable member having abody and a flexure member; a plate having a catch member adapted to matewith the catch member aperture, and a projection in contact with theflexure member, the catch member extending from a distal portion of theversion device along a first axis; and a first locking pin extendingfrom the distal portion of the version device along a second axisnon-parallel to the first axis and adapted to mate with the firstlocking pin aperture; wherein in an unlocked condition of the system,the rotatable member has a first rotated position in which the flexuremember is in an uncompressed state and the plate is in a first position,and in a locked condition of the system, the rotatable member has asecond rotated position in which the flexure member is in a compressedstate and the plate is in a second position proximal of the firstposition.
 2. The system of claim 1, wherein the prosthetic humeralimplant is a permanent implant stem.
 3. The system of claim 2, whereinthe permanent implant stem includes a plurality of indicia for markingthe height of the permanent implant stem.
 4. The system of claim 1,wherein the prosthetic humeral implant is a trial stem implant.
 5. Thesystem of claim 4, wherein the trial stem implant includes a pluralityof indicia for marking the height of the trial stem implant.
 6. Thesystem of claim 1, further comprising a biasing member biasing the plateto the first position.
 7. The system of claim 1, wherein the body of therotatable member includes a first projection in contact with a stopperpin when the rotatable member is in the first rotated position, thefirst projection resisting rotation of the rotatable member in a firstrotational direction.
 8. The system of claim 7, wherein the body of therotatable member includes a second projection in contact with thestopper pin when the rotatable member is in the second rotated position,the second projection resisting rotation of the rotatable member in asecond rotational direction opposite the first rotational direction. 9.The system of claim 1, wherein the flexure member includes a firstgroove, a second groove, and a projecting portion between the first andsecond grooves.
 10. The system of claim 9, wherein in the unlockedcondition of the system, the projection of the plate is positionedwithin the first groove.
 11. The system of claim 10, wherein in thelocked condition of the system, the projection of the plate ispositioned within the second groove.
 12. The system of claim 11, whereinthe system includes an intermediate condition in which the rotatablemember is in a third rotated position between the first and secondrotated positions and the projection of the plate contacts theprojecting portion of the flexure member.
 13. The system of claim 12,wherein the flexure member is at a maximum amount of compression in theintermediate condition of the system.
 14. The system of claim 1, whereinwhen the catch member is positioned within the catch member aperture,the first locking pin is positioned within the first locking pinaperture, and the system is in the locked condition, a compressive forceis maintained between the version device and the prosthetic humeralimplant.
 15. The system of claim 1, wherein the version device includesa plurality of version rod apertures.
 16. The system of claim 15,wherein the version rod apertures are threaded apertures configured tomate with a version rod.
 17. The system of claim 15, wherein each of theplurality of version rod apertures are angled differently than eachother version rod aperture.
 18. The system of claim 1, wherein the plateincludes a first slot and the version device includes a first plate pinpositioned within the first slot.
 19. The system of claim 18, whereinthe first plate pin guides movement of the plate between the firstposition of the plate and the second position of the plate.
 20. Thesystem of claim 1, wherein the prosthetic humeral implant is a permanentimplant stem, and the system further includes a trial stem including atrial catch member aperture adapted to mate with the catch member, and atrial first locking pin aperture adapted to mate with the first lockingpin aperture, the permanent implant stem including a plurality of heightindicia corresponding to a plurality of height indicia of the trialstem.